After the time mentioned in § 8-3452, upon the request of the head of the department, institution, commission, board, or agency by whom the member is employed, any member in service who has attained the required age and completed the service requirements of his class of membership, as specified in § 8-3501 shall be retired.
Upon service retirement a member shall receive during the remainder of his life a service retirement allowance, not in excess of three-fourths (¾) of his average compensation, and in the case of class A membership, such allowance shall not exceed three-fourths (¾) of the average compensation received in the five (5) years in which such compensation was highest during the fifteen (15) years of service immediately preceding his retirement or his minimum service retirement age, if earlier. Such service retirement allowance shall be in an amount depending on his membership class as computed as follows:
In no event shall any change or changes in the level of covered compensation result in a lesser total benefit than that which would have been computed on the basis of covered compensation and the provisions of the Social Security Act as in effect on January 1, 1966. "Total benefit" shall be the sum of (a) retirement allowances, determined in accordance with this section, plus (b) annual primary insurance amount determined in accordance with the provisions of the Social Security Act.
However, any fireman or policeman employed by a political subdivision covered under the Tennessee state retirement system shall receive a service retirement allowance of two and one-fourth per cent (2¼%) of his average compensation multiplied by the total number of years of his creditable service.
However, any commissioned member of the enforcement and field services division of the game and fish commission shall receive a service retirement allowance of two and one-eighth per cent (21/8%) of his average compensation multiplied by the total number of years of his creditable service.
Until such time as this section becomes effective as provided in § 8-3452, § 8-3502 of the Tennessee Code as enacted by chapter 6 of the Public Acts of 1955, prior to amendment, shall remain in full force and effect.
Any class A employee whose (a) "total benefit" determined as of the date his retirement allowance is to commence, would be less than (b) any "total benefit" determined as of any date prior thereto, shall be eligible to have added to his retirement allowance a supplemental monthly benefit which shall be the difference by which (b) exceeds (a). "Total benefit" determined as of any date, shall be based on the employee's creditable service and his age as of the date his retirement allowance is to commence and on his earnings as of the date from which "total benefit" is being calculated, and shall be the sum of (c) and (d), as follows:
The minimum monthly retirement allowance payable to a member of the Tennessee state retirement system who is or who has been a member of the general assembly shall be equal to ten dollars ($10.00) for each year of legislative service which is included as creditable service under the system.
T.C.A. § 8-3502